<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="app">
    <ul>
      <li v-for="(item,index) in list">
        <span> {{item}} </span>
        <button @click="btn(index)">删除</button>
      </li>
    </ul>
    <button @click="fn">添加</button>
  </div>
  <script src="./js/vue-2.7.14.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        list: [1]
      },
      methods: {
        fn() {
          this.list.push(Math.floor(Math.random() * 20))
        },
        btn(index) {
          this.list.splice(index, 1)
        }
      }
    })
  </script>
</body>

</html>